1. Field of the Invention
The present invention relates to a network system and a transmission control method, and more particularly to a network system of a configuration with plural node devices connected with plural channels. More specifically it relates to a network system of a configuration in which plural terminal equipments are respectively connected to the plural channels through each of the node devices.
2. Related Background Art
Recently, active development has been conducted on the network systems for effecting communication by connecting plural pieces of terminal equipment, and there are already known various configurations such as a bus-type configuration in which the plural terminal equipments are connected to a bus line, a ring-type configuration in which the terminal equipments are connected to a ring-shaped transmission path, and a star-type configuration in which the terminal equipment are connected through active or passive couplers. Also for increasing the transmission capacity, there is known a multi-channel configuration in which node devices, to which the terminal equipment are connected, are connected with plural channels. Also a configuration utilizing lights of mutually different wavelengths as the plural channels and multiplexing such lights is known as a wavelength-division-multiplexed network system.
The present invention relates in particular to a network system of a configuration in which the node devices are connected with plural channels.
In the conventionally known network systems utilizing plural channels, a large switching device has to be employed for the transmission control of the signals, in order to process the signals transmitted in the plural channels.
An object of the present invention is to provide a network system and a transmission control method, facilitating such control.